A security guard at the Washington, D.C. headquarters of the Family Research Council, a conservative Christian group that promotes antigay positions, was shot Wednesday morning as a gunman who reportedly expressed disagreement with the organization's views tried to enter the building.

The shooter walked into the lobby in the 800 block of G Street in the Chinatown neighborhood around 10:45 a.m., and was confronted by the guard, who was shot in the arm, the Washington Postreports. D.C. Police Chief Cathy Lanier provided the information to the Post, saying the guard and others wrestled the man to the ground and waited for police to arrive.

The victim is identified as Leo Johnson. And the suspect, identified by the Associated Press as 28-year-old Floyd Corkins, has been taken into FBI custody, where Fox News reports that a source said the shooter "made statements regarding their policies, and then opened fire.” Authorities are treating the incident as a “case of domestic terrorism,” the conservative news network reported, but according to the Associated Press, charges have not yet been filed.

The Associated Press reports that Corkins was a volunteer at The DC Center for the LGBT Community and was described by surprised coworkers as "gentle" and "kind." David Mariner, the center's executive director, expressed dismay at the news in a statement.

"I was shocked to hear that someone who has volunteered with the DC Center could be the cause of such a tragic act of violence," Mariner said. "No matter the circumstances, we condemn such violence in the strongest terms possible. We hope for a full and speedy recovery for the victim and our thoughts are with him and his family."

Fox News linked the incident to the Chick-fil-A controversy, reporting that "sources also said the gunman may have been carrying a bag from Chick-fil-A." The Georgia-based fast food restaurant has been criticized for statements and financial contributions owner Dan Cathy has made against marriage equality. FRC president Tony Perkins has been a staunch defender of Cathy.

NBC 4 correspondent Jackie Bensen also reported a link with the chicken restuarant. She wrote on Twitter that sources said the shooter had Chick-fil-A promotional materials in a backpack, and two loaded 15-round ammunition clips.

An FRC blogger wrote that the gunman had arrived at the front desk and claimed to be an intern for the group who had lost the key card needed to get inside. Otherwise, the FRC offered no immediate details in a brief statement from Perkins.

"The police are investigating this incident. Our first concern is with our colleague who was shot today. Our concern is for him and his family," he said.

Gay advocacy organizations quickly denounced the violence and expressed support for the victim in a joint statement from more than 20 national and state organizations.

"We were saddened to hear news of the shooting this morning at the offices of the Family Research Council," they said. "Our hearts go out to the shooting victim, his family, and his co-workers.

"The motivation and circumstances behind today’s tragedy are still unknown, but regardless of what emerges as the reason for this shooting, we utterly reject and condemn such violence," they continued. "We wish for a swift and complete recovery for the victim of this terrible incident."

The Log Cabin Republicans separately issued a measured statement. The group is participating in the national party's platform drafting process for the first time this year, where its views on items including marriage will contrast those of the FRC.

"As fellow conservatives, Log Cabin Republicans are often in the same room with the Family Research Council. Though we rarely see eye to eye, we absolutely condemn the violence that occurred today," said executive director R. Clarke Cooper. "Keeping in mind that at this time we know little about the shooter or his motives, whatever our political disagreements, in this country, we use ballots, not bullets, to address them. We offer prayers for the injured security guard, his family, and everybody at the FRC building, barely a fifteen minute walk away from Log Cabin Republicans national headquarters. In many ways, this is a reminder that we aren't so far apart."